The invention relates to turf conditioning systems and method, in general and particularly to an aeration subsystem servicing one or more areas of interest of a golf course having a control module providing intermittent cycles of turf aeration, and/or a simple electronic intermittent control circuit for doing the same to lower operating costs without sacrificing effectiveness.
Prior systems are known for treating soil and turf by blowing and/or sucking air through a perforated duct network located underneath the turf. A high-pressure high-volume air pump or blower unit arrangement is typically used to move air into the soil profile or remove moisture from the soil profile. For example, commonly owned U.S. Pat. Nos. 5,433,759; 5,507,595; 5,542,208; 5,617,670; 5,596,836; and 5,636,473, the disclosure of each of which is incorporated herein by reference, show different versions of equipment used for this purpose. Since an air pump or non-reversing blower discharges air from one connection and pulls in air from another, changing the system from a blowing function to a suction function requires disconnecting the duct network from the pressure outlet of the blower and connecting it to the suction inlet. For this purpose, various valves and/or couplings can be used to avoid the hassles involved with selectively connecting and disconnecting the duct network from the various ports of the blower. Manual operations limit the degree to which the usage can be automated. In addition, considerable judgment is involved in knowing when to blow air into the duct network and when to remove air from the duct network by applying a partial vacuum. For example, blowing air into the duct network when there is too much moisture in the soil profile can severely damage parts of the turf.
Commonly owned U.S. Pat. No. 6,273,638, the disclosure of which is incorporated herein by reference, discloses additional features of an air handling system that includes an air handling device connectable to a duct network that is underneath a grass field, at least one sensor disposed to measure a variable associated with the field, and a control module connected to the air handling device to control operating parameters of the air handling device responsive to an output from the sensor. The variables associated with the field include temperature and moisture. The operating parameters of the air handling device include direction of the air flow, temperature of the air directed into the duct network, and the time of operation of the unit. The system optionally includes programmable control logic so that the sensor output automatically controls the operating parameters of the system. The sensor output can be viewed on the computer display to allow a user to manually control the operating parameters if desired.
The prior turf treatment systems are most commonly known for the ability to remove excess water from the soil profile to improve playability on golf greens and sports fields. For example, a system manufactured by SubAir Systems of Graniteville, S.C., has been featured during major golf tournaments citing its ability to quickly return the greens to firm and fast conditions and for keeping fairways and pedestrian areas free from standing water. This feature minimizes downtime in play and makes the course safer for spectators during times of inclement weather.
Some sports fields, including the soccer field of Manchester United (U.K.), the soccer field of Kilmarnock (U.K.), the baseball and softball fields at the University of Nebraska, and the football field of the Denver Broncos in Denver, Colo., have employed similar methods of operation to those described herein. However, the varied conditions found in golf courses are appreciably different from the conditions found in a single unvarying expanse such as a football, a baseball, a softball or a soccer field, requires novel application of the systems and methods to golf courses.
Not as well known in managing golf course turf are the agronomic benefits that are obtained by introducing fresh air into the soil profile. Fresh air is introduced in the profile whenever excess moisture is removed. Excess moisture and low levels of oxygen are major contributors to turf disease. Turf can suffer even when the level of moisture in the soil profile is not excessive due to poor air quality within the soil profile. There are several reasons for this owing to the fact that plant roots require oxygen for respiration. Through the process of respiration the plant uses up available oxygen located in the pore space between sand particles in the profile and replaces it with carbon dioxide. The deterioration of soil air quality is accelerated when the plant is under stress since the rate of plant respiration increases. Oxygen is also depleted and additional gases are generated as a byproduct of decomposing organic matter within the soil profile due to microbial activity. Microbial activity will vary depending on weather conditions with warm, moist weather being the ideal. Lastly, gases such as methane and hydrogen sulfide may exist in surrounding soil naturally. Because soil air quality can vary independent of soil moisture levels it is beneficial to exchange soil gases on a regular and frequent basis to ensure optimum growing conditions for turf. However, the general industry practice has migrated to turf treatment primarily after rain events. Some golf courses do turf treatments once or twice a week, but this will not achieve optimal results especially when the turf is under stress.
Accordingly, an object of the present invention is to provide an automatic turf conditioning system which can not only remove excess water from golf greens and the like, but can condition the root zone to promote healthy grass as well.
Another object of the invention is to automatically control aeration of a soil profile growing sports turf to increase the oxygen and reduce carbon dioxide in the profile to promote the healthy growth of turf.